<?php
namespace cms\paginator;

use think\Paginator;

class AmazeUi extends Paginator
{

    /**
     * 上一页按钮
     * 
     * @param string $text            
     * @return string
     */
    protected function getPreviousButton($text = "&laquo;")
    {
        if ($this->currentPage() <= 1) {
            return $this->getDisabledTextWrapper($text);
        }
        
        $url = $this->url($this->currentPage() - 1);
        
        return $this->getPageLinkWrapper($url, $text);
    }

    /**
     * 下一页按钮
     * 
     * @param string $text            
     * @return string
     */
    protected function getNextButton($text = '&raquo;')
    {
        if (! $this->hasMore) {
            return $this->getDisabledTextWrapper($text);
        }
        
        $url = $this->url($this->currentPage() + 1);
        
        return $this->getPageLinkWrapper($url, $text);
    }

    /**
     * 页码按钮
     * 
     * @return string
     */
    protected function getLinks()
    {
        if ($this->simple)
            return '';
        
        $block = [
            'first' => null,
            'slider' => null,
            'last' => null
        ];
        
        $side = 3;
        $window = $side * 2;
        
        if ($this->lastPage < $window + 6) {
            $block['first'] = $this->getUrlRange(1, $this->lastPage);
        } elseif ($this->currentPage <= $window) {
            $block['first'] = $this->getUrlRange(1, $window + 2);
            $block['last'] = $this->getUrlRange($this->lastPage - 1, $this->lastPage);
        } elseif ($this->currentPage > ($this->lastPage - $window)) {
            $block['first'] = $this->getUrlRange(1, 2);
            $block['last'] = $this->getUrlRange($this->lastPage - ($window + 2), $this->lastPage);
        } else {
            $block['first'] = $this->getUrlRange(1, 2);
            $block['slider'] = $this->getUrlRange($this->currentPage - $side, $this->currentPage + $side);
            $block['last'] = $this->getUrlRange($this->lastPage - 1, $this->lastPage);
        }
        
        $html = '';
        
        if (is_array($block['first'])) {
            $html .= $this->getUrlLinks($block['first']);
        }
        
        if (is_array($block['slider'])) {
            $html .= $this->getDots();
            $html .= $this->getUrlLinks($block['slider']);
        }
        
        if (is_array($block['last'])) {
            $html .= $this->getDots();
            $html .= $this->getUrlLinks($block['last']);
        }
        
        return $html;
    }

    /**
     * 渲染分页html
     * 
     * @return mixed
     */
    public function render()
    {
        if ($this->hasPages()) {
            if ($this->simple) {
                return sprintf('<ul class="pager">%s %s</ul>', $this->getPreviousButton(), $this->getNextButton());
            } else {
                return sprintf('<ul class="am-pagination am-fr tpl-pagination">%s %s %s</ul>', $this->getPreviousButton(), $this->getLinks(), $this->getNextButton());
            }
        }
    }

    /**
     * 生成一个可点击的按钮
     *
     * @param string $url            
     * @param int $page            
     * @return string
     */
    protected function getAvailablePageWrapper($url, $page)
    {
        return '<li><a href="' . htmlentities($url) . '">' . $page . '</a></li>';
    }

    /**
     * 生成一个禁用的按钮
     *
     * @param string $text            
     * @return string
     */
    protected function getDisabledTextWrapper($text)
    {
        return '<li class="am-disabled"><a>' . $text . '</a></li>';
    }

    /**
     * 生成一个激活的按钮
     *
     * @param string $text            
     * @return string
     */
    protected function getActivePageWrapper($text)
    {
        return '<li class="am-active"><a>' . $text . '</a></li>';
    }

    /**
     * 生成省略号按钮
     *
     * @return string
     */
    protected function getDots()
    {
        return $this->getDisabledTextWrapper('...');
    }

    /**
     * 批量生成页码按钮.
     *
     * @param array $urls            
     * @return string
     */
    protected function getUrlLinks(array $urls)
    {
        $html = '';
        
        foreach ($urls as $page => $url) {
            $html .= $this->getPageLinkWrapper($url, $page);
        }
        
        return $html;
    }

    /**
     * 生成普通页码按钮
     *
     * @param string $url            
     * @param int $page            
     * @return string
     */
    protected function getPageLinkWrapper($url, $page)
    {
        if ($page == $this->currentPage()) {
            return $this->getActivePageWrapper($page);
        }
        
        return $this->getAvailablePageWrapper($url, $page);
    }
}